User manual

yve_id: this is an identification number that is automatically assigned by yve and is unique in the system. You can read these yve_ids for existing contacts by selecting 'Contacts -> xls'. I.d.R. You do not need the yve_id.
customer_number: they can give an identification number to a contact itself. Yve make sure this number is assigned only once in your account. For example, To retrieve your contact data from a CRM system, you can load the ID from the CRM system into this attribute.
Other: You can set under 'Account->Contacts are identified by' whether additional fields are used for identification. Caution: You can only change the setting if all of your existing contacts meet the rules of the new setting. Your options are:
- None - Duplicates are allowed: no other fields are used for identification. This allows duplications. This setting makes sense if you do not use yve as a customer database and mainly carry out public registrations. Each registration leads to a new contact, this prevents yve from asking for the password for an existing contact.
- familyname + firstname + email: To avoid duplicates, yve makes sure that the combination of last name, first name and email is only used once in your account. That's why yve recognizes contacts if you provide these values. This setting allows you to create contacts without email or even contacts with the same email address if they have different names. Since names can easily be spelled similarly, you will run the risk of duplicates with similar names using this setting.
- email: To avoid duplicates, yve makes sure that the email in your account is only assigned once. That's why yve recognizes contacts if you enter these values and email is therefore a mandatory field. This is the strictest setting and allows strong control over your contact information. Duplicates are only possible with different email adresses.

What does yve check on contacts?
When you upload your list, yve performs a series of checks in the background yve before the list is created in Contacts. If a condition is not met, the entire list will not be uploaded and you will receive a list of errors by email:

Your list can not contain duplicates based on the rules of identification (see above)
A valid email address must be provided
Each line must contain a value for familyname (surname)
If you are using gender, the values must be 'Male', 'Female', or 'Unknown'
Each row in your list with a value is checked - remove all rows that do not contain contacts (or the column name at the top)

Only if the whole list is error-free, the contacts are imported and you receive the success message by email.

If you want to change the family name, first name or email of an existing contact, you must specify the yve_id or customer_number, otherwise yve will create a new contact with the new data.